The invention relates to a longwall support control for controlling the movements of longwall support units in the longwall of a mine.
A control system of this type is disclosed in DE 102 07 698.7 as well as in DE 199 82 113.5-24 A1 (U.S. Pat. No. 6,481,802).
This longwall support control permits activating the individual longwall support control units, in the present application also referred to as mining shields, from a central control or by individual control units, which are each associated to a mining shield (mining shield control devices). In this connection, it is possible to activate, from one of the mining shield control devices respectively the adjacent or a plurality of adjacent mining shields. Basically, the control signals are supplied to all mining shield control devices via a common bus line. However, the mining shield control devices are programmed such that only that mining shield control device is addressed and caused to execute the switching commands, to which the code word is associated that is transmitted along with the control command. All other mining shield control devices retransmit the control signal with the code word.
An error in a mining shield control device makes the entire system inoperative. Likewise, a manual control is not possible before the error is corrected.
It is therefore an object of the invention to provide an improvement of the longwall support control, which permits finding errors in a mining shield control in a simple manner, and which otherwise permits operating the system despite the error.